bobbin thread bunching up

How To Fix Bobbin Thread Bunching Up: A Sewist’s Guide

Have you ever struggled with tangled bobbin thread while sewing? Finding a mess of thread under your fabric mid-project can be incredibly frustrating. Unfortunately, bobbin thread bunching up is a standard sewing machine problem many crafters and sewists face. In this article, we’ll discuss the leading causes of bobbin thread bunching up and solutions to help fix bobbin threads getting twisted and tangled. Keep reading for pro tips on adjusting tension, threading correctly, cleaning your bobbin area, and more!

Main Causes of Bobbin Thread Bunching Up

Before you can solve any sewing machine problem, it helps to understand what’s causing it. Here are the most common culprits behind tangled bobbin threads.

Improper Bobbin Tension

Bobbin tension refers to how tight the thread is wound around the bobbin case. This tension works with the upper thread tension to create even, balanced stitches. The lower thread will be too slack if the bobbin tension is too loose. Too much stress makes the thread too tight. Both can cause bunching, looping, and uneven stitches.

Signs of improper bobbin thread tension include:

  • Loose upper threads.
  • Skipped stitches.
  • Bunched threads under the fabric.
  • Uneven tension in your stitches.

Luckily, adjusting bobbin tension is simple on most sewing machines. Locate the tension screw on the bobbin case and turn it slightly clockwise to tighten the tension or counter-clockwise to loosen it. Make minor adjustments and test after each turn.

Incorrect Threading

It’s easy to miss a step when threading your sewing machine, especially the bobbin. Even seasoned sewers must remember to follow the proper bobbin threading sequence, leading to problems. Skipping threading the tension disks, not inserting the thread fully into the tension spring, or not wrapping the thread clockwise are common mistakes.

Double-check your machine’s manual and follow each bobbin threading step. Ensure the thread slides into the tension disks and wraps under the tension spring. Pull on the thread to ensure it’s securely placed before inserting the bobbin case. Taking your time to thread correctly can prevent frustrating thread bunching.

Buildup in Bobbin Area

Lint and thread fuzz quickly accumulate in the bobbin area. Over time, this buildup can interfere with the thread path, cause friction, and lead to tangled threads bunching up. Regularly removing lint in the bobbin case and surrounding area is essential maintenance.

To access the bobbin case:

  1. Could you remove it from the sewing machine?
  2. Use a small brush to brush out the lint gently. If an object has accumulated fuzz and you’re having trouble removing it, consider using a cotton swab and rubbing alcohol to dissolve it.
  3. Ensure the area is spotless, and insert the bobbin case back into your machine.

Using the Wrong Needle

Using the Wrong Needle
Photo credit: pexels

Your embroidery machine needle and thread need compatible sizes and types to prevent bunching. Improper needle size or type selection can result in stitching errors, fabric fraying, and thread tangling. Always match your needle to the weight and fiber content of your thread and fabric type.

Symptoms of a wrong needle include frayed or shredded thread, skipped stitches, thread bunching up, or fabric damage. Consult your manual on the correct needle choice. Replace bent, dull, or damaged needles right away. Changing to the right needle can instantly improve stitch quality and prevent tangling.

Solutions for Fixed Bobbin Thread Bunching

Once you’ve diagnosed the issue, here are pro tips and tricks to solve bobbin thread bunching for good.

Adjusting Tension

As discussed, improper tension is a significant cause of tangled threads. After threading the bobbin case correctly, you should fine-tune the tension. Make micro-adjustments to the bobbin tension screw if needed.

Test on fabric scraps after each adjustment. The goal is balanced tension, where the upper and lower threads interlock in the center of your fabric. When in balance, you’ll get beautiful stitches without bunching or looping. Adjusting thread tension takes trial and error, so be patient.

Changing the Needle

An old, bent, or incorrectly sized needle is often the culprit behind thread bunching up. Make changing your sewing machine needle part of your regular maintenance. Needles should be changed after 6-8 hours of sewing or when they become dull.

Choose needles suited for your fabric type and weight. Match the size to your thread thickness as well. Keeping various needle types and sizes on hand ensures you always have the right one. Correctly inserting needles is also crucial—ensure they are fully inserted and tightened properly.

Cleaning Lint Buildup

As mentioned earlier, accumulated lint is a prime suspect. Clean your bobbin area thoroughly to clear out any excess thread debris. Remove the stitch plate and use tweezers to pull out lint trapped near the feed dogs.

You can also remove the tension disks and bobbin case to clean them with rubbing alcohol. A few passes with a lint brush in the bobbin compartment will help, too. Prevent future buildup by cleaning regularly during projects.

Retreading Correctly

Sometimes, you need to rethread your home sewing machine properly. Before threading, make sure the presser foot is up, as this opens the tension disks. Engage both the upper and lower thread tension systems.

Triple-check that the bobbin thread is threaded correctly following the precise path. Insert the bobbin case and pull on it gently to test the tension spring. Then, carefully thread the upper thread following your model’s guidance. Go slowly and refer to manuals, videos, or tech support if you need more clarification. Proper threading is vital for smooth sewing.


What causes the bobbin thread to bunch up?

The leading causes of bobbin thread bunching up are improper tension, incorrect threading, lint buildup, and using the wrong needle.

How do I fix tangled bobbin thread?

To fix bobbin thread bunching, adjust the tension, rethread correctly, clean lint from the bobbin area, change the needle, and ensure proper threading.

Why does my bobbin thread keep bunching?

Frequent bobbin thread bunching is usually due to lint buildup, poor tension balance, threading errors, or damage/wear-causing friction.

How do I know if my bobbin tension is off?

Signs of improper bobbin tension include:
Loose top threads.
Uneven stitches.
Thread bunching under the fabric.
Loops on the underside.

Why is my bottom thread looping?

Bottom thread looping is typically caused by the bobbin tension being too loose. Tighten the bobbin case tension screw slightly to resolve looping.

What size needle should I use?

Choose a needle size for your thread thickness and fabric weight. Match the needle type to the fabric composition. Consult your manual.

How often should I change my needle?

Needles should be changed after every 6-8 hours of sewing or when they become damaged or dull.


Bobbin thread bunching up mid-project is annoying but usually fixable. The leading causes include improper tension, incorrect threading, lint buildup, and wrong needle types. Carefully troubleshooting and adjusting to these areas will make your sewing machine sewing smooth again. Remember regular machine maintenance, too.

Have you solved the bobbin thread bunching issues before? What worked for you? Let us know your tips and tricks in the comments! Correctly threaded bobbins and balanced tension make all the difference in your sewing projects.


Main image: pexels

Priti Nandy
Priti Nandy
Articles: 169

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